The disclosures herein relate generally to computer systems and, more particularly, to an apparatus and method for securing a heat sink to an electronic component in a computer system.
Heat sinks are commonly used to aid in dissipating heat from electronic components in equipment such as a computer. The heat sink is configured to readily dissipate heat from one or more electronic components to the surrounding atmosphere or to an attached cooling device. Heat sinks may have an extruded, machined, or otherwise formed body with heat dissipating fins or the like for transferring heat from the electronic component. However, to provide for acceptable and efficient heat transfer, the heat sink must be in sufficient contact with the related component.
Various types of heat sink mounting assemblies are known for engaging a heat sink against a related electronic component such as a microprocessor. Many of these types of heat sink mounting assemblies are specifically configured for a given size or type of electronic component. These types of component specific heat sink assemblies may need to be redesigned when the related electronic component is redesigned or otherwise modified.
Some heat sink mounting assemblies are intended to be of a universal configuration. However, they may have one or more limitations, including expensive manufacturing cost, complex installation technique, limited or inconsistent force-generating characteristics, and excessive space requirements.
U.S. Pat. No. 5,883,782 discloses an apparatus for removing heat from the top surface of an electronic package. An electronic package is attached to the top-side of a printed circuit board. The printed circuit board has a first set of through holes positioned symmetrically about the electronic package. A heat sink is placed in thermal contact with the top surface of the electronic package. The heat sink has a second set of through holes that correspond and are align with the first set of through holes. Posts having a first end portion and a second end portion are positioned within the first and second set of through holes such that the first end portions are in abutting engagement with the top surface of the heat sink. The second end portions protrude from the bottom-side of the printed circuit board. The heat sink is held in place by a spring clip. The spring clip includes a substantially flat cross member and a pair of legs extending outward from either side of the cross member. Each one of the legs terminates at a flange section. The flange section of each leg has an opening for receiving the second end portion of a post.
U.S. Pat. No. 5,586,005 discloses a post type fastening member that provides, at one end, an insertion friction connection to the circuit card. At the other end, extending through the heat sink, a compression spring means is provided that urges the heat sink toward the circuit card. A plurality of the post type fasteners are positioned around the periphery of the chip package to retain the heat sink parallel to the circuit card and compressing the chip package. The packaging structure of the invention permits larger area heat sinks than the chip package area to be supported by the circuit card with the only relationship with the chip being that of a compression thermal transfer contact and radiation shield.
U.S. Pat. No. 5,331,507 dicloses a resilient heat sink clip having a pair of legs joined together at one end by an arcuate member. The other ends of the legs each terminate in a hook. The arcuate member bears against a heat sink while pressing it into thermal contact with an electronic device package to conduct heat into the heat sink and then into the atmosphere.
U.S. Pat. No. 5,331,507 dicloses a clip having parallel edge frames with pockets at each end and connected by transverse beams. The clip is used to removably secure a heat sink to an orthogonal device package by inserting the corners of the device package in the pockets to secure the heat sink between the transverse beams and the surface of the device package.
Microprocessor modules without an integral heat spreading plate can pose a unique challenge for mounting a heat sink. The heat sink must be brought into direct contact with the microprocessor chip with a nominal amount of contact pressure applied uniformly over the area of the microprocessor chip. Excessive pressure can deflect the heat sink, reducing the level of heat transfer. Furthermore, excessive pressure can also cause stress concentrations resulting in damage to the microprocessor chip.
Accordingly, a need has arisen for an apparatus and method that allows a heat sink to be economically manufactured and reliably mounted to a heat generating electronic device.